Occlusions, such as chronic total occlusions (CTO), are arterial vessel blockages that obstruct blood flow through a vessel. A diseased condition called arthrosclerosis generally results in formation of an occlusion, which can occur in both coronary and peripheral arteries. In general, a minimally invasive procedure called atherectomy may be employed to treat such vessel occlusions. Atherectomy procedures may include the use of rotational, orbital, laser, and/or directional atherectomy devices, for example.
A typical rotational atherectomy device includes a shaft having a cutting member disposed at its distal end. The cutting member is rotated via a drive shaft coupled to a handle assembly while being advanced inside the vessel to penetrate through the occlusion. The rotating cutting member thus forms an opening while penetrating through the occlusion. In general, the opening formed may have dimensions either equal to or slightly larger than the dimensions of the cutting member. Thus, a larger cutting member must be provided to form a larger opening through the occlusion, adversely impacting the ability to navigate the cutting member through the vasculature.
In some instances, it may be desirable to form an opening significantly larger than the original dimensions of the cutting member in some instances. Accordingly, a need remains to use smaller profile cutting members, which may facilitate navigation through the vasculature to an occlusion, yet are configured to create a larger passage through the occlusion.